low OG

[camelbrewery]

I've been doing BIAB a few times recently using half a can of liquid malt and replacing the other half with around 4lbs of grain.

When I've finished mashing grains (1.5quarts per pound) and sparge, I start the boil, once boiling I add the liquid malt, 1kg of dextrose, then boil adding hops for an hour.

My OG for two of my recent news have been 1024 and 1032, rather low compared to previous.

Why (even with the dextrose) is it so low?

 

[NewWestBrewer]

Need more information. What grains and what mash temp? What did the crush look like? Maybe post the recipe for us to see.

 

[C-Rider]

Sure that's enough LME for 5 gallons?

 

[camelbrewery]

Start with 3 lbs of grain (mix of maris otter, crystal and Vienna) mash for an hour at around 160-165 (not exact as done in electric stove in pot). Mash and sparge using 4.5 quarts for each.
Sparge then top up to 11litres for boil.
Add 1.8lbs of LME (Ale) + 1kg of dextrose and boil for 1hour. Hops added along the way.
Chill, to up to 23 litres and pitch yeast. OG 1032.

I am going to buy a chilli bin (esky/cooler) soon to help control my temperatures.

Is it hurting me only using 11 litres to boil? My pot is 20 litres but my oven/stove can't get that boiling (a 3 ring gas burner is also on my list).

Any suggestions are warmly received!

 

[RM-MN]

Start with 3 lbs of grain (mix of maris otter, crystal and Vienna) mash for an hour at around 160-165 (not exact as done in electric stove in pot). Mash and sparge using 4.5 quarts for each.
Sparge then top up to 11litres for boil.
Add 1.8lbs of LME (Ale) + 1kg of dextrose and boil for 1hour. Hops added along the way.
Chill, to up to 23 litres and pitch yeast. OG 1032.

I am going to buy a chilli bin (esky/cooler) soon to help control my temperatures.

Is it hurting me only using 11 litres to boil? My pot is 20 litres but my oven/stove can't get that boiling (a 3 ring gas burner is also on my list).

Any suggestions are warmly received!

The part marked in red is the problem. The enzymes that break the starch down to sugars only operate in a narrow temperature range and it is lower than you specified. At the low end, say 146 to 150, beta amylase will be the active enzyme. As the temperature goes up, alpha amylase becomes active and beta is slowly denatured. Keep raising the temperature and both enzymes are denatured or in simple terms, dead.

To mash, start by getting a thermometer that is accurate in the range of 140 to 170. Read about strike temperature, the temperature you need to bring the water so that when the grain is added the temperature of the mash will fall between 148 and 160, usually nearer to 152 to 155 for a good mix of enzyme activity that will get you wort that is fermentable but will leave some sweetness or maltiness to the beer. Keep the mash temperature as stable as you can by insulating the mash tun.

 

[camelbrewery]

My mistake, I actually had the temperature at 155 degrees. Not 165, just re-read my diary.

Still not to sure why it was so low.

 

[RM-MN]

Start with 3 lbs of grain (mix of maris otter, crystal and Vienna) mash for an hour at around 160-165 (not exact as done in electric stove in pot). Mash and sparge using 4.5 quarts for each.
Sparge then top up to 11litres for boil.
Add 1.8lbs of LME (Ale) + 1kg of dextrose and boil for 1hour. Hops added along the way.
Chill, to up to 23 litres and pitch yeast. OG 1032.

I am going to buy a chilli bin (esky/cooler) soon to help control my temperatures.

Is it hurting me only using 11 litres to boil? My pot is 20 litres but my oven/stove can't get that boiling (a 3 ring gas burner is also on my list).

Any suggestions are warmly received!

Does this sentence mean that you topped up your wort to make 23 litres? If so, your efficiency was probably fine but your concentrated wort and the top off water didn't mix well and your hydrometer sample contained more water than wort. It's difficult to get them to mix in the fermenter but that's OK because the yeast will find the sugars and mix them for you.

 

[Yooper]

I assume the mix of three pounds of grain was a pound of each?

I'd guess that the recipe you're using is something like:
1 pound MO
1 pound Vienna
1 pound crystal
1.8 pounds LME
2.2 pounds dextrose

First, is that's right that's too much sugar for the amount of grain/extract so I'd definitely double the extract and leave out the sugar (or at least go with no more than .5 pound) as you've got over 30% corn sugar in the recipe. A recipe with over 30% sugar is not going to be the best tasting beer.

In any case, without the sugar the OG would be at best 1.025, if you're making a 23L batch. With the sugar, the best you could expect is about 1.039.

In other words, you just don't have enough fermentables to get to a higher OG for the beer. You need more extract, and/or more grain.

If the "lb" for the extract is an error, and it's actually 1.8 Kg, that would be better (but still not ideal).

 

[camelbrewery]

Cheers, that makes a bit more sense. If I was to dump the sugar altogether how much more grain would you recommend? The liquid malt was 1.8lbs. ?
I want a beer that is at least 5%....

 

[camelbrewery]

I used 1.8lvs of LME, if I dropped the dextrose altogether and wanted around 5%ABV..... How much grain would you think I'd need for this recipe? 1.8lbs of LME and (x) grain?